I think the islands need to get club teams in either the ITM Cup or the Super 15, the problem with just playing tests is the island teams never get to field their best players because all their best players are playing for clubs in Europe, but if the island teams each got a team to be in either the ITM Cup or S15, it could develop all of the local island rugby players to where they wouldn't even need these players from Europe. I think the only way for the island teams to be up with all the major teams in the world is for their local players to be up with all the best club players in the world, that way they won't have to rely on bringing together players from random clubs all over the world once every 4 years.
and if they can't do that they could at least have island teams like Fiji Warriors, Samoa A, Tonga A play regular games against S15 teams